How large is a leaf-cutter queen? (Benjamin, Ann Arbor, Michigan, USA)

Leaf-cutter ants of the genus Atta are well known for cutting and carrying bits of leaf material back to their nest. They then chew this leaf material up into a fine paste to use as the substrate to grow their food - fungus! This is where they get their other common name, fungus-growing ants. Since fungus growing ants have been cultivating fungus for ~50 millions of years, this makes them the worlds first farmers.

Worker of Atta texana carrying leaf material back to the nest. Photo by Alex Wild (www.alexanderwild.com).

In a leaf-cutter ant colony there are many sizes of individuals from minute workers to large soldiers to the giant queen herself. The queen of leaf-cutter colonies such as Atta cephalotes can be 22 mm in length. Not quite as long as the the African driver ants mentioned in the post below, but still very large.